1. Field Of The Invention
This invention relates to a molded plastic closure for a container and to a package which is made up of a container with such a molded plastic closure affixed thereto. More particularly, this invention relates a tamper indicating, molded plastic closure with an inwardly projecting helical thread by which such a closure may be affixed to and removed from the finish of a bottle with an outwardly projecting helical thread that is complemental to the helical thread of the closure, and to a package which is made up of such a bottle and such a molded plastic closure affixed thereto
2. Description Of The Prior Art
U.S. Pat. No. 4,595,110 (J.E. Herr) discloses a bottle with a molded plastic, tamper indicating, internally threaded closure applied to an externally threaded finish portion of such bottle. The closure of this reference derives its tamper indicating characteristics from a series of tabs which are formed at the lower margin of a ring which, in turn, is frangibly integrally attached to the lower margin of an annular skirt of the closure. The tabs are mechanically repositioned after the closure is formed, to extend inwardly and upwardly from the ring to engage an annular bead or ring on the finish of the bottle in an interference fit, and to thereby cause the ring to break away from the skirt of the closure upon the first removal or attempted removal of the closure from the bottle to provide a visible indication of a prior opening or attempted opening of the bottle. A closure of this type requires extra material, relative to other types of tamper indicating molded plastic closures, to form the tabs which extend from the breakaway ring, and, hence, is more expensive in terms of material costs than such other types of tamper indicating molded plastic closures.
U.S. Pat. No. 4,401,227 (H.T. Pehr) also discloses a bottle with a molded plastic, tamper indicating, internally threaded closure applied to an externally threaded finish portion of such a bottle. It would appear that the closure of this reference uses less material than that of the Herr reference, since the closure of this reference avoids the need for the breakaway ring of the Herr reference by relying on breakaway tabs which are directly attached to the skirt of the closure and which engage an annular shoulder on the bottle and break away from the closure upon the first removal or attempted removal of the closure from the bottle. However, because of the complexity of the design of this closure, it is believed that it cannot be produced by a molding technique in which the closure can be stripped away from the mold tooling used in it manufacture, which is a faster and hence less expensive molding technique than the alternative molding technique in which the closure must be unscrewed from the mold tooling, and it is not clear that the closure of this reference can be affixed to a standard glass or plastic container finish, which is preferable whenever possible since bottles with standard finishes are less costly to manufacture than comparable bottles with special finishes.
U.S. Pat. Nos. 3,417,893 (H.G. Lieberman); 4,153,174 (F.D. Keeler); 4,190,169 (H.T. Pehr); 4,196,818 (T.D. Brownbill); and 4,488,655 (J. Itsubo et al.) disclose other types of molded plastic tamper indicating, internally threaded closures, but for various reasons the closures of these references also fail to provide the features and advantages of the closure of the present invention.